Experimental Study On Drying Characteristics Of Lignite In Low-Temperature Flue Gas

With continuous growth of China’s energy consumption in recent years, the large scale use of high quality coal resources has not been allowed. The lignite resource, which has been neglected before, has attracted more and more attention in the world. As is known to all, lignite is a kind of nonrenewable resources, and its moisture content is higher, its total moisture content is generally up to 60% ~ 10%, the calorific value is low, and the volatile matter is relatively high. If the lignite is without dried directly into the furnace combustion, will produce more heat loss, resulting in reduced efficiency of the boiler. In order to overcome the disadvantages of direct utilization of lignite resources and to solve the problem of clean and efficient utilization of lignite, it is an urgent task to explore the new technology of drying lignite with high efficiency.According to this research, the construction and commissioning of COMBDry drying lignite test bench is completed. On the basis of the design of the system flow chart of the COMBDry drying lignite experiment table, the composition of the experiment platform is introduced in detail, including the burner and flue gas producer, COMBDry dryer, the selection of drying heat source, gas supply system, feeding system, dust removal system, cooling water circulation and heat exchange system and circuit control system, etc. The measurement system of the test bench is introduced, including the measurement of temperature, pressure and flow rate, the design and installation of the flue gas sampling gun and the acquisition of the experimental data. To carry out the debugging work of the COMBDry drying lignite test bench: the calibration of the cold air volume and the amount of coal, the test run test of the lignite, the improvement of the COMBDry dryer and the draught fan. Finally, the construction and commissioning of the COMBDry drying lignite test bench was completed, which laid a good foundation for the next step drying lignite experiment.Finally, the experimental study on the drying characteristics of lignite with low temperature flue gas was carried out by the COMBDry drying lignite experiment platform which has been debugged successfully. The influence of drying temperature on the drying characteristics of lignite was studied, and the optimum drying temperature of the low temperature flue gas was determined; Under the condition of the optimum drying temperature, obtained through the influence of research on bituminous coal ratio on the drying characteristics of lignite, Different kinds of lignite lead to different effects on the parameters of the ratio of flue gas to lignite particles on drying characteristics of lignite; on the different parameters than bituminous coal drying characteristics of lignite under the low temperature flue gas; Under the condition of the optimum drying temperature, control the influence of parameters ratio of flue gas to lignite particles within a reasonable range, study the flow of flue gas of lignite drying characteristics, determine the flue gas temperature optimum drying flue gas flow.